|Keywords (Extracted from title, table of contents and abstract of thesis)
sugarcane borers, peshawar valley, saccharum officinarum, shoot borer, gurdaspur borer, chilo infuscattellus, bissetia steniellus, top borer, scirpophaga nivella, root borer, emmalocera depressella, trichogramma chilonis
Sugarcane (Saccharum officinarum) is one of the most important cash crops of Pakistan and is grown on 1,05,000 hectares of land. In NWFP 80-90% of the crop is grown in 6 districts namely Peshawar, Charsadda, Nowshehra, Mardan, Sawabi and lower parts of Malakand district. Distribution and level of infestation of sugarcane borers i.e. Shoot borer (Chilo infuscattellus), Gurdaspur borer (Bissetia steniellus), Top borer (Scirpophaga nivella) and Root borer (Emmalocera depressella) was determined through an extensive survey in both plant and ratoon crops conducted at 20 different locations each in district Peshawar and Charsadda and 10 different locations in each of the remaining 4 districts revealed that except top borer, the remaining 3 borers were recorded in each location of all districts. Mean infestation of shoot, gurdaspur and root borers in both plant and ratoon crops ranged from 1.90-2.77, 2.60-4.66 and 20.14-26.04% respectively in Peshawar (Eastern parts), Nowshehra; Charsadda (Eastern parts), Peshawar (Eastern parts); Sawabi and Nowshehra. The results further revealed that infestation of all borers was comparatively lower in plant crop than infestation recorded in ratoon crops in each district. Mean infestation of borers and their effect on cane yield of 8 each early and mid maturing varieties of sugarcane plant crops recorded during 2001-2002 and 2002-2003 showed that, in the early maturing varieties infestation of Shoot, Gurdaspur and Root borers ranged from 0.76-2.03; 1.02-2.74 and 4.13-6.22%, respectively on varieties MS.91.CP.1154, Mardan-93; MS.91.CP.1154, Mardan-93 and MS.91.CP.1154 and Mardan-93. Similarly the highest and lowest cane yield of 105.09 and 87.73 tons ha-1 was recorded from variety MS.91.CP.582 and mardan-93 respectively. In mid maturing varieties infestation of Shoot, Gurdaspur and Root bores ranged from 0.78-0.89; 0.97-1.27 and 4.16-4.94 % respectively on varieties MS.92.CP.716, MS.92.CP.727; MS.92.CP.727, CP.77/400; SP.HS2 and CP.77/400. The highest and lowest cane yield of 99.52 and 94.32 (t ha-1) was recorded from variety MS.92.CP.727 and CP.77/400, respectively. Mean infestation of borers and their effect on cane yield of the early maturing varieties of sugarcane ratoon crops recorded during 2002-2003 and 2003-2004 revealed that infestation of Shoot, Gurdaspur and Root borers ranged from 1.75-2.90; 2.25-3.45 and 6.83 -10.70 % respectively on varieties MS.91.CP.582 and Mardan-93. The highest and lowest cane yield of 77.65 and 66.12 (t ha-1) was recorded from variety CP.87.1248 and Mardan-93, respectively. In the mid maturing varieties infestation of Shoot, Gurdaspur and Root bores ranged from 1.65-2.14; 1.81-2.40 and 6.62-8.18 %, respectively on varieties MS.92.CP.727, CP.77/400; MS.91.CP.691, CP.77/400; MS.92.CP.727 and SP.HS2. The highest and lowest cane yield of 73.88 and 61.32 (t ha-1) was recorded from varietyMS.91.CP.691 and CP.77/400, respectively.
Use of Mechanical (T1), Cultural (T2), Biological (T3) and Chemical control (T4) alone and in combination of Mechanical, Cultural and Biological control (T5) and Mechanical, Cultural and Chemical control (T6), the untreated check (T7) against Shoot, Gurdaspur and Root borers and the resultant effect of these treatments on cane and sugar yield (t ha-1) and Commercial Cane Sugar (CCS %) revealed that infestation of Shoot, Gurdaspur and Root borers in both plant and ratoon crops was significantly the lowest in T6 and the highest in T7. The cane and sugar yield (t ha-1) was recorded the maximum in T6 and the minimum in T7. CCS (%) did not differ significantly among all the treatments which indicated that variety Mardan-93 used in this experiment was the sweetest variety and borers infestation did not affect CCS %. T6 was combination of Mechanical, Cultural and Chemical control measures. This was followed by T5 where Mechanical, Cultural and Biological control measures were combined. The use of Mechanical, Cultural and Biological control agent (Trichogramma chilonis @ 16000 parasitized eggs/acre) proved significantly superior to the untreated check, however proved inferior to T5 & T6. The study further revealed that in general infestation of all the borers was lower in plant crops than Ratoon crops and therefore the cane & sugar yield (t ha-1) recorded for plant crops were comparatively higher than those recorded for Ratoon crops.